The present invention relates to a snowmobile flotation system. In recent years snowmobiles have become very popular for recreational use. In areas of the country where the ground is snow covered for significant portions of the year they are widely used for basic off road transportation. They have also proven to be invaluable for winter search and rescue operations in the back county and mountainous terrain.
While snowmobiles are highly useful and versatile vehicles they are relatively expensive and inherently limited to use on snow covered terrain. As a result, they are limited to use in geographic areas where there is some significant annual snow fall and during periods of the year where there is at least a few inches of standing snow cover. In places where bodies of water at least partially freeze over during certain times of the year, there is often a need to travel across the frozen water. In some cases, this may be for emergency situations, such as where someone has fallen through the ice and must be reached for rescue.
In others, it may be that one's home is on an island in the middle of a frozen lake. A snowmobile can be used to travel over solid ice, but it is rare that one can traverse a frozen body of water with complete confidence that the entire body of water is consistently solidly frozen. The rider, therefore, takes the risk that the snowmobile and rider may fall through thin ice at any time. A boat, on the other hand, may be able to move through water and break through thin ice, but will have little utility on solid ice.
In the prior art, it is known to provide auxiliary flotation for a vessel such as, for example, a boat. For example, U.S. Pat. No. 4,864,961 discloses an auxiliary flotation system for a boat including a plurality of floats which may be inflated either automatically or manually from a source of pressurized gas to maintain flotation of the vessel. This different from the teachings of the present invention which contemplates incorporation of a flotation system on a device, namely a snowmobile, which is not normally expected to float during its normal mode of operation.
A boat, on the other hand, may be able to move through water and break through thin ice, but will have little utility on solid ice. Therefore, there is a need for a vehicle that allows a rider to travel both over water and over solid ice. Some progress has been made toward the development of such a vehicle and a number of patents disclose the conversion of conventional snowmobiles into aquatic vehicles.
For example, U.S. Pat. No. 3,521,595 discloses the conversion of a conventional snowmobile into an aquatic vehicle for travel on water. This conversion involves the replacement of the steerable ground engaging snow skis with a buoyant supporting and steering arrangement that includes pontoons attached to the snowmobile body in the mounting arrangement coupled to the steering linkage of the snowmobile. The pontoons are disposed relative to the engine driven endless cleat track extending lengthwise under the body such that the track functions in the water as the propulsion means.
Although this invention discloses the conversion of a snowmobile into an aquatic vehicle, it has significant disadvantages. First, the invention requires the removal of the snow skis in favor of pontoons. Such removal may be difficult and may make it difficult or impossible to replace the snow skis so that the snowmobile may eventually be used as an ordinary snowmobile again. Moreover, once converted, the only seating and storage space on the aquatic vehicle is on the snowmobile, which could make rescue operations difficult.
U.S. Pat. No. 4,893,692 discloses a floatable snowmobile made up of a one-piece molded plastic body. The body includes a rigid skin forming a shell defining an enclosed cavity in which there is provided an expanded closed-cell foam core of water-buoyant material. Floating skis are constructed as pontoons of similar construction to the body and replace the conventional snowmobile skis such that the whole snowmobile can float with a portion thereof out of the water so as to support a rider clear of the water in the event the snowmobile falls through ice. Although the U.S. Pat. No. 4,893,692 discloses a snowmobile that will not sink, it also has its disadvantages. Given its floatable construction, it is not as maneuverable as a standard snowmobile and requires significant modification in order to be converted back into a conventional snowmobile.
Like the apparatus disclosed in the U.S. Pat. No. 3,521,595, there is no seating or storage on the vehicle other than the seating and storage provided by the snowmobile, which could make rescue operations difficult. Further, and more importantly, there is no ability to effectively steer the vehicle when it is submerged in water.
Finally, U.S. Pat. No. 6,595,812 discloses an amphibious vehicle for traversing a body of water or solid terrain, such as a layer of ice floating atop a body of water. The vehicle includes a floatable boat hull having an elongate aperture therethrough, and a snowmobile for traveling over the solid terrain received in the opening and sealed in water impervious relation to the hull. The snowmobile includes an endless drive track, which supports the hull in spaced relation when travelling over solid terrain being and which rearwardly propels water to forwardly propel the vehicle through the water.
Alluding to the above, a pair of skis supports the front of the hull in spaced relation with the solid terrain being traversed and each ski includes upturned forward ends mounting upstanding rudders for steering the vehicle as it traverses a body of water. The hull includes upwardly extending, downwardly opening pockets for receiving the front upturned ends of the skis and stabilizing arms, which are coupled between the frame and the skis. Upwardly inclined guides are provided on the underside of the hull for upwardly guiding the skis out of the water onto the ice floating on the water as the vehicle exits the water and moves onto the ice.
Various additional prior art references teaches a snowmobile powered watercraft which includes a pair of forward pontoons mounted to the front suspension in place of conventional skis and an U-shaped rear pontoon mounted to the aft portion of the snowmobile body. Propulsion is provided by the endless track assembly of the snowmobile which extends in part beneath the rear pontoon. Also disclosed is a structural assembly for converting the snowmobile into a watercraft which includes the forward and rear pontoons.
Still another prior art reference, namely U.S. Pat. No. 8,678,868 teaches a pair a boat capable of having a snowmobile securely mounted on its hull and steerable by the snowmobile's steering mechanism. The boat includes a bow, an aft, a port side, a starboard side, and a mid-ship. The hull of the boat includes a top and a bottom, wherein the bottom of the hull includes under-hull skis with tips and tails, and the bottom of the hull further includes a bow step positioned proximate to the tips of the under-hull skis. The boat also includes: a snowmobile opening including a cutaway of the hull extending into the hull from the aft and disposed halfway between the port and starboard sides; a transom disposed at the aft; and a boat steering mechanism including two boat ski attachment mechanisms on the port and starboard sides of the boat and two snowmobile ski attachment mechanisms on the port and starboard sides.
According, it is another object of this invention to provide for a structural assembly for converting a snowmobile to a self-propelled watercraft which is relatively simple and requires only minimal disassembly of the snowmobile in the conversion process.
Thus, it is a primary object of this invention to provide for a structural assembly for converting a snowmobile into a self propelled watercraft, thereby substantially extending the portion of the year during which the vehicle is useable.